Overview of Relation Extractor

The relation extractor is designed to annotate relations between certain Event, Entity, and Modifier annotations.

It currently has been trained for detecting body site and severity, using machine learning with a model trained on manually annotated clinical data.

The default means of running the relation extractor is to use ctakes-relation-extractor/desc/analysis_engine/RelationExtractorAggregate.xml.

Analysis Engines

analysis_engine/RelationExtractorAggregate

An aggregate analysis engine that will do all of the preprocessing before running ModifierExtractorAnnotator, DegreeOfRelationExtractorAnnotator and EntityMentionPairRelationAnnotator

analysis_engine/EntityMentionPairRelationAnnotator

This analysis engine will iterate through all sentences in a document and tag pairs of entities with a relation. This depends on having POS tags, Named Entities, Dependency Parses, Constituency Parses and Chunks. Currently this annotator only outputs LocationOf relations.

No parameters need to be set as the defaults are sufficient for analysis engine initialization.

analysis_engine/ModifierExtractorAnnotator

This analysis engine will take a CAS and annotate spans with Modifiers. This analysis engine is a prerequisite for the DegreeOfRelationExtractorAnnotator.

No parameters need to be set as the defaults are sufficient for analysis engine initialization.

analysis_engine/DegreeOfRelationExtractorAnnotator

This analysis engine will iterate through all sentences in a document and tag all relevant pairs of entities and modifiers with a DegreeOf relation. This analysis engine depends on identification of Modifiers from the ModifierExtractorAnnotator.

No parameters need to be set as the defaults are sufficient for analysis engine initialization.

analysis_engine/RelationExtractorPreprocessor

This aggregate analysis engine contains all of the prerequisites necessary for running relation extraction.